An appealing but dangerous path. If they're that rich, what happens to you when the husband finds out? What happens when the woman finds out your origins, or if she gets bored or scared?
There is a distinct possibility she says "I love you" because you treat her like a human being rather than a payday. It's quite possible you are on a very short list of people who have done so. Whether you continue treating her that way or not is a question you have to face.
You are already deep in this situation. Be mindful that it will change, likely against you. Be careful and cover your ass. Consult with a lawyer, preferably from her own jurisdiction. At minimum review the contract terms with them and figure out your rights and liabilities.
I'm not saying don't do it, just to be cautious. Plan for as many outcomes as you can. It very likely is the best chance you'll have to climb the socioeconomic ladder in a world hell-bent on preventing you from doing so. Her wealth is pillaged from your peers and her privilege from a system designed to insulate the rich from the consequences of their actions. Just realize you will also be key with the consequences of your actions as well and you are far less insulated from them.
Best of luck.

